Backup and restore systems are commonly deployed on many computer systems and other devices that contain data. Such backup and restore systems may copy data from one source, such as a hard disk or other data storage system, to another source, such as an offsite data repository, removable tape or optical storage system, or other device.
In a restore operation, a new set of data storage media may be created or the original media overwritten to create a data source that is capable of operating as the original media. A hardware failure may cause the replacement of data storage hardware, which may have the data recreated from a backup data location. In another case, a corruption, misconfiguration, or other damage to stored data may be cause for data to be overwritten with a known good version of data from a previous backup.
With the large size of storage media available, backup and restore operations may be very time consuming. During backup operations, a working copy of a data set may be used to create a backup while other operations continue. Such a system may consume some processor bandwidth, but may keep the system in an operable state. However, during a restore operation, a large amount of data may be transferred consuming a large amount of time, during which a system may not be operable until the restore operation is complete.